Search Results (100)

Background: Abemaciclib (ABM) in combination with tamoxifen (TAM) is an extremely significant treatment regimen for hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2-) breast cancer. It is approved for patients to reduce the risk of cancer recurrence. A bioanalytical method for the simultaneous determination of this new anti-breast cancer combination and its pharmacokinetic application has not yet been reported. Methods: An ultra-performance liquid chromatography tandem mass spectrometry (UPLC–MS/MS) method was developed for quantifying ABM, TAM, and its metabolites, including abemaciclib active metabolites M2, M18, and M20 and tamoxifen active metabolite N-desmethyl tamoxifen (NDTAM), in rat plasma using econazole as the internal standard (IS). Chromatographic separation was achieved on a Kinetex C18 column (100 × 2.1 mm ID, 2.6 µm) using gradient elution with 5 mM ammonium formate in water (eluent A) and 5 mM ammonium formate in water/methanol (1:9, v/v, eluent B) at a flow rate of 0.4 mL/min. Detection was performed on a TSQ Fortis Plus mass spectrometer employing multiple reaction monitoring mode under positive electrospray ionization. Results: The developed method was validated according to the guidance of the FDA. Linearity in rat plasma (ng/mL) was achieved from 1 to 1000 for ABM, TAM, and M20; 3 to 1000 for M2; 5 to 500 for M18; and 1 to 500 for NDTAM; with correlation coefficients ranging from 0.9991 to 0.9931 for all analytes using a weighting factor of 1/X². The lower limit of detection (LLOD) ranged between 0.3 and 1.5 ng/mL for all drugs. The accuracy ranged from 96 to 108% and the precision was less than 7.6% RSD for all analytes. For the first time, the newly developed approach was effectively used in a pharmacokinetic study on the simultaneous oral administration of ABM and TAM in rats that received 30.0 mg/kg of ABM and 8.0 mg/kg of TAM. Conclusions: To the best of our knowledge, this is the first reported UPLC–MS/MS method for the assay of ABM, TAM, and its active metabolites in plasma. This method offers a bioanalytical tool for assessing the pharmacokinetics of ABM and TAM. Therefore, this study makes a definite significant contribution to the field of bioanalytical research. Further validation in human plasma is required for future clinical or therapeutic drug monitoring applications, as the approach was developed in an animal model. Full article

Background/Objectives: While ¹⁷⁷Lu-DOTATATE has demonstrated clinical efficacy in peptide receptor radionuclide therapy (PRRT) for neuroendocrine tumors (NETs), current dosing regimens do not account for potential sex-based pharmacokinetic differences. Our study systematically characterizes sex-dependent pharmacokinetic variations of ¹⁷⁷Lu-DOTATATE in preclinical models to provide the first preclinical evidence base informing future sex-stratified clinical investigations. Methods: Sex-stratified pharmacokinetic and biodistribution studies were conducted in male and female SD rats following intravenous administration of ¹⁷⁷Lu-DOTATATE at multiple dose levels: 2.86, 5.71, and 11.43 mCi/kg. Metabolic stability and renal excretion patterns were characterized. Safety assessments included acute toxicity, vascular irritation, hemolysis, and allergenicity testing. Therapeutic efficacy was evaluated exclusively in female AR42J xenograft-bearing CB-17 SCID mice. Results: Significant sex-dependent pharmacokinetic differences were observed at high (11.43 mCi/kg) and low (2.86 mCi/kg) dose levels, with females exhibiting 30–40% higher AUC and C_max values compared to males (p < 0.05). Both sexes demonstrated preferential accumulation in SSTR-expressing tissues, particularly the pancreas (females: 10.87 ± 2.51% ID/g; males: 9.10 ± 0.76% ID/g) and adrenal glands, with rapid clearance from non-target organs. Radio-HPLC analysis confirmed high metabolic stability with no detectable radiolabeled metabolites, and over 90% of radioactivity was recovered through renal excretion. Safety assessments demonstrated excellent tolerability across dose levels. In female xenograft models, treatment achieved tumor growth inhibition of 92.35–96.44% and 100% survival rate versus 10% in controls, though mid/high doses caused weight loss. Conclusions: Our study provides systematic preclinical evidence of sex-dependent pharmacokinetic differences in ¹⁷⁷Lu-DOTATATE, with females demonstrating significantly higher systemic exposure than males at specific dose levels. These findings establish the systematic preclinical evidence base for sex-dependent pharmacokinetic differences in ¹⁷⁷Lu-DOTATATE, providing a scientific rationale for incorporating sex as a stratification variable in future dosimetry-guided clinical studies. Full article

Background: Untargeted metabolomics enables comprehensive profiling of biological systems, but accurate metabolite annotation remains a critical bottleneck due to incomplete spectral libraries and structural isomerism. The use of in silico annotation tools can increase the coverage of annotated compounds, but it remains unclear whether these tools, in the absence of reference standards, can reliably annotate real-world experimental LC-HRMS data and whether they are sufficient for this task. Methods: This study assesses the performance and limitations of four widely used in silico structure prediction tools (MassFrontier, MetFrag, MS-FINDER, and SIRIUS/CSI:FingerID) when applied to an experimentally acquired feature set previously used to differentiate patients with depressive disorders from healthy controls. To ensure uniform evaluation across tools under realistic but optimized conditions, the quality of MS/MS data was improved using a parallel reaction monitoring method, allowing acquisition of interpretable fragmentation spectra for 26 of the 28 detected features. Results: For most features, all tools were able to suggest structure candidates. However, none of the tools proved sufficient as a standalone solution for reliable metabolite annotation. Due to their different algorithms, each tool had strengths and weaknesses in fragmentation interpretation, candidate generation, and ranking, resulting in incomplete or inconsistent annotations. While the combined application of all four tools provided a substantial improvement in putative annotation over conventional spectral library matching, the in silico structure prediction tools often prioritized chemically implausible, biologically irrelevant, or artifactual candidates. Consequently, manual expert evaluation was required to assess the chemical plausibility and biological relevance of the proposed structures. This ultimately reduced the number of biologically plausible metabolites putatively associated with disease to ten. Conclusions: Overall, these results demonstrate that existing in silico annotation tools can substantially support the annotation of experimental metabolomics data, but are insufficient on their own. Reliable identification of metabolites in complex biological matrices still depends on high-quality MS/MS data acquisition, the combined use of complementary tools, and mandatory post-annotation expert curation. Full article

Glutathione (GSH), often referred to as the “master antioxidant,” plays a vital role in protecting cells against oxidative stress. This human pilot study aimed to evaluate the oral absorption and safety profile of a novel formulation of micellar glutathione (LipoMicel^®, LMG) compared with two commonly used dietary supplement forms: standard glutathione (STD) and liposomal glutathione (Setria^® Glutathione, LSG). In the first phase, a randomized, double-blind, crossover study was conducted in healthy adults (n = 14) to assess whole-blood GSH following single oral doses using baseline-adjusted pharmacokinetic parameters (incremental AUC_0–24 [iAUC_0–24], C_max, T_max) and a targeted panel of glutathione-related metabolites. In the second phase, a 30-day, single-arm follow-up assessed the safety and tolerability of the most bioavailable formulation (LMG) in the same participants. Compared with STD (500 mg), LMG (300 mg) produced significantly higher baseline-adjusted systemic GSH exposure and peak response (iAUC_0–24: 1287.5 ± 179.0 vs. 517.8 ± 180.0 µg·mL·h; p = 0.0064; ΔC_max: 103.9 ± 11.8 vs. 42.8 ± 11.5 µg/mL; p = 0.0003), corresponding to ~2.49-fold higher incremental exposure and ~2.43-fold higher peak response at the administered doses. When dose-normalized to a 300 mg equivalent, the incremental exposure (iAUC) and C_max were up to 4-fold higher for LMG than STD. In the targeted metabolite panel, most analytes showed no formulation-dependent differences; however, dose-normalized methionine exposure was significantly higher with LMG than STD (iAUC: 149.9 ± 30.8 vs. 32.7 ± 28.3 µg·mL·h; p = 0.0151; ~4.58-fold). No significant differences were observed in oxidized glutathione (GSSG) exposure, while the GSH/GSSG ratio was higher following LMG versus STD (p = 0.001). No significant changes in clinical safety markers (e.g., ALT, AST, ALP, creatinine) were observed following 30 days of daily LMG administration at 600 mg/d. The novel micellar glutathione formulation demonstrated enhanced oral bioavailability compared with a standard glutathione preparation and was well tolerated over 30 days in healthy adults. These findings present LipoMicel^® as a promising approach for oral glutathione delivery and warrant further investigation into its long-term physiological and clinical effects. This clinical trial was registered at ClinicalTrials.gov under trial ID NCT06345950 on 3 April 2024. Full article

Malaria is a major global health concern caused by Plasmodium parasites, among which Plasmodium falciparum is responsible for the most severe and fatal cases. The emergence of drug resistance to existing antimalarial therapies necessitates the discovery of novel molecular targets and chemically distinct inhibitors. Current study employed an integrated in silico drug discovery pipeline combining high-throughput structure-based virtual screening of 1549 deep-sea marine microbial metabolites with MM-GBSA binding free-energy estimation, QikProp-based ADME/Tox profiling, and 100 ns molecular dynamics (MD) simulations to link rapid screening with dynamic verification of binding stability. Molecular docking against Plasmodium falciparum dihydroorotate dehydrogenase (PfDHODH; PDB ID: 7KZ4) yielded five top-ranked compounds with Glide scores ranging from −12.02 to −10.61 kcal·mol⁻¹, which is higher than the Primaquine (−6.920 kcal·mol⁻¹; a clinically approved antimalarial reference compound). MM-GBSA analysis further refined hit selection, producing binding free energies (ΔG_bind) between −63.28 and −31.37 kcal·mol⁻¹. The selected lead compounds included (±)-puniceusine P, aspergilol F, tersaphilone C, 4-carbglyceryl-3,3′-dihydroxy-5,5′-dimethyldiphenyl ether, and 15-O-methyl ML-236A. The top hits were subjected to 100 ns MD simulations in Desmond, demonstrating stable protein–ligand complexes, particularly for (±)-puniceusine P and 15-O-methyl ML-236A (protein backbone root mean square deviation (RMSD; ~0.8–1.0 Å). ADME profiling indicated acceptable predicted physicochemical and pharmacokinetic properties. Overall, these in silico findings highlight deep-sea marine microbial metabolites as promising PfDHODH inhibitor candidates requiring experimental validation. Full article

Heroin is a highly addictive drug that exerts its primary effects through activation of μ-opioid receptors. Its principal active metabolite, 6-monoacetylmorphine (6-MAM), significantly contributes to heroin’s neurological effects and acute toxicity. Current pharmacotherapies for heroin use disorder, employing opioid receptor agonist or antagonist, are often limited by risks of dependence, tolerance, and/or adverse side effects. In this context, enzyme-based therapy emerges as a promising alternative by rapidly converting drugs into inactive or less harmful metabolites in the blood. As a macromolecule, the enzyme does not cross the blood–brain barrier, thereby avoiding side effects in CNS. Through structure-based computational screening, Xoo-PepA (PDB ID: 3JRU), a leucine aminopeptidase from Xanthomonas oryzae pv. oryzae, was identified as a potential enzyme capable of hydrolyzing heroin and 6-MAM. Computational and experimental analyses confirm that Xoo-PepA hydrolyzes heroin sequentially to 6-MAM and subsequently to morphine. Enzymatic properties including dependence on metal ions, optimal pH, thermal stability, and substrate specificity were characterized accordingly. Notably, supplementation with Ni²⁺ or Zn²⁺ and TCEP extended Xoo-PepA’s half-life at 37 °C from 1 h to over 24 h, highlighting the essential role of metal ions in maintaining structural stability. Moreover, Ni²⁺ enhanced Xoo-PepA’s hydrolysis toward peptidase substrate L-leucine-p-nitroaniline by 770-fold, yet conferred no significant activation toward heroin. Mutations in metal ion-coordination residues (e.g., K262A, D267A/E346L) exhibited different activity profiles toward these two types of substrates, suggesting a distinct regulatory mechanism of metal ions may be involved in these activities. This study provides the first demonstration that Xoo-PepA, a non-mammalian, metal-dependent aminopeptidase, can hydrolyze heroin and 6-MAM, shedding light on its functional versatility and biochemical characteristics. Full article

Background/Objectives: Alterations in polyunsaturated fatty acid (PUFA) metabolites have been linked to the development of hepatocellular carcinoma (HCC). However, the association between PUFA metabolites and HCC development during nucleos(t)ide analogue (NUC) therapy in patients with chronic hepatitis B virus infection remains unclear. Methods: This study enrolled 195 NUC-naïve patients who received NUC therapy. Associations between metabolic factors—especially PUFA metabolites—and HCC development during NUC therapy were evaluated. Baseline serum concentrations of 158 PUFA metabolites were quantified using targeted lipidomic analysis. Results: Nineteen patients developed HCC during the follow-up period. The cumulative incidences of HCC at 5 and 10 years were 7.7% and 12.4%, respectively. Variable importance in projection analysis identified 12-hydroxyheptadecatrienoic acid (12-HHT) as the top-ranked metabolite differentiating patients with and without HCC development. Furthermore, 14 metabolites were significantly associated with HCC development based on the log-rank test with 12-HHT being the most significant predictor. The cumulative incidences of HCC at 5 and 10 years were 13.7% and 24.7%, respectively, in patients with 12-HHT concentration ≤ 3.82 ng/mL compared with 3.3% at both time points in those with 12-HHT concentration > 3.82 ng/mL (p < 0.001). In multivariate analysis, low 12-HHT concentration (≤3.82 ng/mL; p = 0.027; hazard ratio [HR], 4.28; 95% confidence interval [CI], 1.18–15.55) and a fibrosis-4 index ≥ 4.08 (p = 0.005; HR, 5.19; 95% CI, 1.64–16.41) were significantly associated with HCC development during NUC therapy. Conclusions: Pre-treatment 12-HHT represents a novel predictive biomarker for HCC development during NUC therapy. Full article

Nicotine is the main substance responsible for the development of tobacco addiction. The α3β4 nicotinic acetylcholine receptors (nAChRs) are a potential key target for mitigating nicotine reward. Preliminary studies in our laboratory suggest that α-conotoxin [S9K]TxID serves as a selective and potent antagonist targeting α3β4 nAChRs, which may be beneficial in addressing nicotine addiction. However, the mechanisms of [S9K]TxID treatment in nicotine addiction are still to be determined. This study aimed to identify the differential metabolic profiles of [S9K]TxID treatment in nicotine addiction using an untargeted metabolomic profiling method. As demonstrated by behavioral experiments, [S9K]TxID effectively attenuated nicotine-induced conditioned place preference (CPP) expression without exerting inhibitory effects on the central nervous system (CNS). The results of untargeted metabolomics revealed that eight metabolites were significantly altered after [S9K]TxID treatment, particularly phenylalanine. [S9K]TxID also attenuated nicotine-induced metabolic disorders by regulating phenylalanine, tyrosine and tryptophan biosynthesis. In conclusion, our findings suggest that [S9K]TxID could be a potential therapeutic compound for nicotine addiction. Full article

Background/Objectives: Vitamin D plays an important role in muscle metabolism and recovery, yet its kinetics during and after football-specific physical activity remain poorly understood. Therefore, this study aimed to determine whether physical effort during a football match influences the concentration of vitamin D metabolites and to explore the effect of a single high-dose cholecalciferol supplementation combined with physical exercise on the levels of vitamin D metabolites in professional football players. Methods: Twenty professional football players participated in a three-phase, randomized placebo-controlled pilot study. Baseline fitness and blood samples were collected, followed by pre- and post-match measurements during two games. In the final phase, half of the players received a single 500,000 IU dose of vitamin D₃ before a simulated match. Blood samples were collected before and after each session to analyze vitamin D metabolites using the isotope-dilution liquid chromatography–tandem mass spectrometry (ID-LC-MS/MS) method. Results: Physical exercise during the football match significantly increased serum concentrations of 25-(OH)D₃, 24,25-(OH)₂D₃, and 3-epi-25-(OH)D₃ (by up to 25%, p < 0.001). Following supplementation, these effects were further amplified, with 25-(OH)D₃ rising by 98% and 3-epi-25-(OH)D₃ by 424% (p < 0.001). Significant alterations in vitamin D metabolite ratios after exercise and supplementation suggest enhanced metabolic turnover and dynamic regulation of vitamin D pathways in response to physical effort. Conclusions: Football-specific physical activity appears to stimulate the release of vitamin D metabolites. High-dose cholecalciferol supplementation was well tolerated and may rapidly increase vitamin D status in professional athletes. These findings may have implications for optimizing recovery and performance, though larger trials are needed. Full article

Objectives: This experiment investigated the response of carcass composition, digestive function, hepatic lipid metabolism, intestinal microbiota, and serum metabolomics to excessive or restrictive dietary energy in Ningxiang pigs. Methods: A total of 36 Ningxiang pigs (210 ± 2 d, 43.26 ± 3.21 kg) were randomly assigned to three treatments (6 pens of 2 piglets each) and fed a control diet (CON, digestive energy (DE) 13.02 MJ/kg,), excessive energy diet (EE, 15.22 MJ/kg), and restrictive energy diet (RE, DE 10.84 MJ/kg), respectively. Results: Results showed that EE significantly increased the apparent digestibility of crude protein and total energy (p < 0.01), as well as the activities of jejunum neutral protease and ileal lipase (p < 0.05). With the increase in energy level, the apparent digestibility of ash, dry matter, and ether extract significantly increased (p < 0.01). RE significantly increased high-density lipoprotein cholesterol (HDL-C) content, significantly decreased triglycerides (TG), free fatty acid (NEFA), and total cholesterol (TC) contents, and up-regulated lipoprotein lipase (LPL) mRNA expression in the liver (p < 0.05). EE significantly increased the hepatosomatic index, the contents of low-density lipoprotein cholesterol (LDL-C) and total bile acids (TBA), and significantly up-regulated the mRNA expression of lipogenic genes acetyl-CoA carboxylase (ACC), fatty acid synthase (FAS), and sterol regulatory element-binding protein-1C (SREBP-1C) in the liver (p < 0.05). The abundance of p_Firmicutes was significantly increased and the abundance of p_Bacteroidetes was significantly decreased in test groups, while the ratio of the two was significantly increased in the RE group (p < 0.05). EE also significantly increased the abundance of g_Clostridium_sensu_stricto_1 (p < 0.05). The identical serum differential metabolites between the EE and RE group belong to phosphatidylcholine (PC), mostly being up-regulated in the EE group and down-regulated in the RE group (p < 0.05), one of which was mapped to the pathway of glycerophospholipid metabolism (KEGG ID: C00157). The relative content of serum trimethylamine N-oxide (TMAO, a microbial metabolite) was significantly decreased in the EE group (p < 0.05). Conclusions: The findings suggest RE had no obvious negative effect on carcass traits of Ningxiang pigs. Apart from exacerbated body fat deposition, EE promoted fat accumulation in the liver by up-regulating the expression of lipogenic genes. Dietary energy changes affect hepatic bile acid metabolism, which may be mediated through the glycerophospholipid metabolism pathway, as well as disturbances in the gut microbiota. Full article

This study aimed to optimize a formulation of Spatholobus littoralis Hassk. stems and Sauropus androgynus L. leaves using Simple Lattice Design (SLD). In this context, the response variable was DPPH (2,2-Diphenyl-1-picrylhydrazyl) antioxidant activity, while the optimum extract concentration of the two plants served as the experimental factor. Subsequently, the optimum formula was investigated for its in vitro anti-inflammatory activity against COX-2 (cyclooxygenase-2) and through in silico study. Molecular docking on the COX-2 receptor (PDB ID: 5IKQ) from the secondary metabolite profile was validated for the optimum formula. The formulation recommended by SLD comprised a 1:1 mixture of 70% ethanol extract of S. littoralis Hassk. stems and S. androgynus L. leaves. This optimum formula had an IC₅₀ value of 108.70 µg/mL for the DPPH antioxidant with a synergistic effect due to the production of higher COX-2 inhibitory activity (73.05 ± 2.36%) than the single extract at 100 µg/mL. Daidzein (−8.514 kcal/mol), (10E,12Z)-9-Hydroperoxy-10,12-octadecadienoic acid (−7.604 kcal/mol), arteannuic acid (−7.114 kcal/mol), L-Proline,4-hydroxy-5-oxo-4-(tetrahydro-2,3,4-trihydroxy-2-furanyl)- (−6.480 kcal/mol), and Androst-2-en-17-amine,4,4-dimethyl-N-(2-phenylethyl)-, (5.alpha.)- (−5.440 kcal/mol) were the five compounds from the 70% ethanol extract of S. littoralis Hassk. stems and S. androgynus L. leaves that strongly bound 5IKQ. These compounds were obtained from five groups of compounds, namely flavonoids, fatty acids, terpenoids, amino acid derivatives, and amine derivatives. The formulation of S. littoralis Hassk. and S. androgynus L. extract has potential as an antioxidant and anti-inflammatory agent. Full article

Background: Methotrexate (MTX) is the most used anti-rheumatic drug for the treatment of early rheumatoid arthritis (ERA) patients, with an adequate response rate of only 30–40%. Thus, early detection of response failure is very crucial to prevent permanent disability. Objectives: We aimed to provide an update on the current evidence of potential predictive biomarkers of MTX treatment response (MTX-TR) in patients with ERA. Materials and Methods: PubMed/MEDLINE, Scopus, EBSCO, and Cochrane Library were searched for studies that investigated a multitude of predictive metabolites of MTX-TR in ERA patients during the 2000–2024 period. This study was registered in PROSPERO (ID: CRD42024547651). Results: We determined that 31 out of 102 metabolites studied were the best predictive of MTX-TR in ERA, using clinical response (DAS28-ESR score). Our results on serum protein profiles revealed that higher pre-treatment levels of myeloid-related proteins, MTX–polyglutamates, choline, inosine, hypoxanthine, guanosine, nicotinamide, and diglyceride, and lower pre-treatment levels of N-methyl isoleucine, 2,3-dihydroxy butanoic acid, nor-nicotine, glucosylceramide, and itaconic acid, were associated with a good MTX-TR. However, lower baseline plasma itaconate and its derivatives and haptoglobin, but a higher baseline level of galactosylated glycans (FA2G) of IgG1, were associated with a good response to MTX. The results on immune cell biology indicated that higher pre-treatment of regulatory B cells, lower pre-treatment of Treg, and RDW were correlated with a good MTX-TR. The results on inflammatory biomarkers showed that a lower IL-1ra/IL1B ratio and IL-6 levels after MTX indicated a good response. Conclusions: This study provides an update on the current evidence of the potential predictive metabolites for the best MTX-TR in ERA patients. We revealed that few biomarkers resulted in a remission state of patients with ERA. These biomarkers are promising but not yet ready for routine clinical use; they warrant validation in larger prospective trials. We recommend that, for the implementation of personalized medicine, these biomarkers should be the first-line biomarkers for use in routine clinical practice after validation. Full article

Introduction: Osteoarthritis (OA) is a chronic degenerative joint disease with limited treatment options focused primarily on symptom management. Emerging evidence suggests that dietary interventions may influence inflammation and pain through modulation of the gut microbiome and metabolome. Methods: We conducted a 4-week open-label pilot trial evaluating the effects of an anti-inflammatory dietary intervention (ITIS diet) in 20 patients with knee OA (ClinicalTrials.gov ID: NCT05559463, registered prior to enrollment; sponsor: University of California, San Diego; responsible party: Monica Guma; study start date: 1 October 2021). The following were assessed before and after the intervention: (1) clinical outcomes; (2) gut and salivary microbiomes; and (3) salivary, stool, and plasma metabolomes. Responders were defined as patients achieving ≥30% reduction in Western Ontario and McMaster Universities Arthritis Index (WOMAC) pain scores. Results: The ITIS diet was well-tolerated, with good adherence (66.2%) and a significant improvement in clinical outcomes, including reduced pain and improved overall health measured with the visual analog scale (VAS). Responders (n = 8) showed distinct gut microbiome and metabolome profiles compared to non-responders (n = 12). Notably, taxa within the Lachnospiraceae family exhibited dynamic, bidirectional shifts post-intervention: Anaerostipes and Limivivens were enriched among responders and negatively correlated with pain scores, while Oliverpabstia and Fusicatenibacter were depleted following dietary intervention. These taxa also showed strong correlations with anti-inflammatory metabolites, including hydroxydecanoic acid derivatives and pyridoxine. Furthermore, subsequent network analysis revealed more structured and selective microbiome–metabolome interactions in responders, specifically post-intervention. Conclusions: This pilot study shows that a short-term anti-inflammatory dietary intervention was associated with meaningful changes in the gut microbiome and metabolome. Members of the Lachnospiraceae family emerged as key taxa associated with pain reduction and anti-inflammatory metabolite production. Our findings suggest that specific microbial responses—rather than global diversity changes—may underlie dietary responsiveness in OA. Although exploratory and limited by sample size, our results support further investigation into personalized, microbiome-informed nutritional strategies for OA management. Full article

Background/Objectives: Iron deficiency (ID) is a common nutritional deficiency in infancy and early childhood associated with increased risk of infection and increased likelihood of receiving antibiotic intervention. In the context of ID, antibiotics have been shown to exaggerate the growth impairments and negative impacts on metabolic health of ID itself. The objective of this research was to assess the tissue-level impact of antibiotics when provided during ID. Methods: ID was induced in piglets by withholding an iron dextran shot shortly after birth, and iron deficiency was maintained after weaning by providing an iron-deficient diet starting on postnatal day (PD) 25. Half of the ID piglets received a 3-day antibiotic course (ID + Abx) consisting of spectinomycin and gentamicin from PD34-36. The kidney, liver, skeletal muscle, and hippocampal metabolomes, as well as activity of proteins in the mTOR signaling pathway, were assessed on PD43. Results: While ID had minimal impacts on the liver, kidney, and skeletal muscle metabolomes, ID + Abx impaired energy metabolism and increased ketosis and oxidative stress in peripheral tissues. Hippocampal metabolites involved in neurotransmitter synthesis pathways were affected by ID and ID + Abx to a greater extent. Additionally, the activities of several proteins in the mTOR pathway were upregulated in the hippocampi of ID + Abx piglets compared to both ID and control piglets. Abx provided to iron-sufficient piglets had minimal effects on tissue metabolomes and did not alter the activity of proteins in the mTOR pathway. Conclusions: These results highlight that antibiotic treatment in ID alters metabolism in peripheral tissues and the developing hippocampus beyond those induced by ID alone. Considering that infants and children are develop rapidly, the combination of ID and antibiotics may have lasting impacts on neurodevelopment and cognition. Full article

Pelagic sargassum arriving in the Mexican Caribbean is a mixture of brown macroalgae containing polysaccharides, minerals, and secondary metabolites with potential in ruminant diets. The objective of the present study was to evaluate the effect of the inclusion of sargassum in integral diets (ID) on in vitro fermentation characteristics. A completely randomized design was used. The treatments were different levels of sargassum (ICD: 0%, ID10: 10%, ID20: 20% and ID30: 30%) added to a basal substrate (a mixture of Pennisetum purpureum Vc. CT-115 hay, corn, soybean, and molasses). Rumen fluid was obtained from five male lambs with a body weight of 40 ± 3 kg. In vitro gas production (IVGP) as well as dry matter degradability (DMD) and organic matter degradability (DOM) increased linearly (p < 0.0001) as the proportion of sargassum increased at 24, 48, and 72 h. Rumen fluid pH decreased (p < 0.05) with 30% inclusion at 48 h, while protozoan concentration was similar (p > 0.05) in all treatments with respect to the control at all evaluation times. These results indicate that the inclusion of pelagic sargassum in integral concentrated diets improves fermentative parameters, and its inclusion in diets for ruminants is feasible. This opens up a window of opportunity for its study as a novel additive or unconventional supplement. However, in vivo studies are necessary to rule out harmful effects on animal health and performance. Full article